That's not creeping doubt that's an advertisement for how "safe" it is to get both. The flu vx is relatively safe, not effective, but safe. But the honest answer is, at this time we really don't know how mRNA vx and traditional vx mix. Theoretically it's probably as safe as the two separately, but we don't know. This is the first public mRNA vaccine, the people in the earlier trials for sure were not mixing vaccines as it taints the results.